Mollusks

Alabama Snails and Mussels

The precipitous decline of North American freshwater mollusks has resulted in increased awareness of this fauna over the past two decades. With one of the most diverse assemblages of aquatic snails and the most diverse assemblage of mussels in the world, Alabama often has been the focal point of this interest. This state is, or was historically, home to 204 species of freshwater snails and 180 species of freshwater mussels.

Of these 383 types of mollusks, 102 snail and 11 mussel taxa have never been collected outside the boundaries of Alabama. When taxa endemic to drainages that Alabama shares with adjacent states are included, these numbers increase to 115 snails and 58 mussels. As would be expected with such a level of endemism, many species have very restricted distributions and specialized habitat requirements, making them highly vulnerable to extinction.

Rough Hornsnail (Pleurocera foremani) is a very rare snail that is endemic to the Cahaba and Coosa rivers (photograph by Thomas Tarpley).